Commit | Line | Data |
---|---|---|
b77e38aa SR |
1 | /* |
2 | * event tracer | |
3 | * | |
4 | * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com> | |
5 | * | |
6 | */ | |
7 | ||
8 | #include <linux/debugfs.h> | |
9 | #include <linux/uaccess.h> | |
10 | #include <linux/module.h> | |
11 | #include <linux/ctype.h> | |
12 | ||
c32e827b | 13 | #include "trace.h" |
b77e38aa | 14 | |
b628b3e6 SR |
15 | #define TRACE_SYSTEM "TRACE_SYSTEM" |
16 | ||
11a241a3 SR |
17 | static DEFINE_MUTEX(event_mutex); |
18 | ||
1473e441 SR |
19 | #define events_for_each(event) \ |
20 | for (event = __start_ftrace_events; \ | |
21 | (unsigned long)event < (unsigned long)__stop_ftrace_events; \ | |
22 | event++) | |
23 | ||
b77e38aa SR |
24 | void event_trace_printk(unsigned long ip, const char *fmt, ...) |
25 | { | |
26 | va_list ap; | |
27 | ||
28 | va_start(ap, fmt); | |
29 | tracing_record_cmdline(current); | |
30 | trace_vprintk(ip, task_curr_ret_stack(current), fmt, ap); | |
31 | va_end(ap); | |
32 | } | |
33 | ||
34 | static void ftrace_clear_events(void) | |
35 | { | |
36 | struct ftrace_event_call *call = (void *)__start_ftrace_events; | |
37 | ||
38 | ||
39 | while ((unsigned long)call < (unsigned long)__stop_ftrace_events) { | |
40 | ||
41 | if (call->enabled) { | |
42 | call->enabled = 0; | |
43 | call->unregfunc(); | |
44 | } | |
45 | call++; | |
46 | } | |
47 | } | |
48 | ||
fd994989 SR |
49 | static void ftrace_event_enable_disable(struct ftrace_event_call *call, |
50 | int enable) | |
51 | { | |
52 | ||
53 | switch (enable) { | |
54 | case 0: | |
55 | if (call->enabled) { | |
56 | call->enabled = 0; | |
57 | call->unregfunc(); | |
58 | } | |
59 | if (call->raw_enabled) { | |
60 | call->raw_enabled = 0; | |
61 | call->raw_unreg(); | |
62 | } | |
63 | break; | |
64 | case 1: | |
65 | if (!call->enabled && | |
66 | (call->type & TRACE_EVENT_TYPE_PRINTF)) { | |
67 | call->enabled = 1; | |
68 | call->regfunc(); | |
69 | } | |
70 | if (!call->raw_enabled && | |
71 | (call->type & TRACE_EVENT_TYPE_RAW)) { | |
72 | call->raw_enabled = 1; | |
73 | call->raw_reg(); | |
74 | } | |
75 | break; | |
76 | } | |
77 | } | |
78 | ||
b77e38aa SR |
79 | static int ftrace_set_clr_event(char *buf, int set) |
80 | { | |
1473e441 | 81 | struct ftrace_event_call *call = __start_ftrace_events; |
b628b3e6 SR |
82 | char *event = NULL, *sub = NULL, *match; |
83 | int ret = -EINVAL; | |
84 | ||
85 | /* | |
86 | * The buf format can be <subsystem>:<event-name> | |
87 | * *:<event-name> means any event by that name. | |
88 | * :<event-name> is the same. | |
89 | * | |
90 | * <subsystem>:* means all events in that subsystem | |
91 | * <subsystem>: means the same. | |
92 | * | |
93 | * <name> (no ':') means all events in a subsystem with | |
94 | * the name <name> or any event that matches <name> | |
95 | */ | |
96 | ||
97 | match = strsep(&buf, ":"); | |
98 | if (buf) { | |
99 | sub = match; | |
100 | event = buf; | |
101 | match = NULL; | |
102 | ||
103 | if (!strlen(sub) || strcmp(sub, "*") == 0) | |
104 | sub = NULL; | |
105 | if (!strlen(event) || strcmp(event, "*") == 0) | |
106 | event = NULL; | |
107 | } | |
b77e38aa | 108 | |
11a241a3 | 109 | mutex_lock(&event_mutex); |
1473e441 | 110 | events_for_each(call) { |
b77e38aa | 111 | |
1473e441 SR |
112 | if (!call->name) |
113 | continue; | |
114 | ||
b628b3e6 SR |
115 | if (match && |
116 | strcmp(match, call->name) != 0 && | |
117 | strcmp(match, call->system) != 0) | |
118 | continue; | |
119 | ||
120 | if (sub && strcmp(sub, call->system) != 0) | |
121 | continue; | |
122 | ||
123 | if (event && strcmp(event, call->name) != 0) | |
b77e38aa | 124 | continue; |
b77e38aa | 125 | |
fd994989 SR |
126 | ftrace_event_enable_disable(call, set); |
127 | ||
b628b3e6 | 128 | ret = 0; |
b77e38aa | 129 | } |
11a241a3 SR |
130 | mutex_unlock(&event_mutex); |
131 | ||
b628b3e6 | 132 | return ret; |
b77e38aa SR |
133 | } |
134 | ||
135 | /* 128 should be much more than enough */ | |
136 | #define EVENT_BUF_SIZE 127 | |
137 | ||
138 | static ssize_t | |
139 | ftrace_event_write(struct file *file, const char __user *ubuf, | |
140 | size_t cnt, loff_t *ppos) | |
141 | { | |
142 | size_t read = 0; | |
143 | int i, set = 1; | |
144 | ssize_t ret; | |
145 | char *buf; | |
146 | char ch; | |
147 | ||
148 | if (!cnt || cnt < 0) | |
149 | return 0; | |
150 | ||
151 | ret = get_user(ch, ubuf++); | |
152 | if (ret) | |
153 | return ret; | |
154 | read++; | |
155 | cnt--; | |
156 | ||
157 | /* skip white space */ | |
158 | while (cnt && isspace(ch)) { | |
159 | ret = get_user(ch, ubuf++); | |
160 | if (ret) | |
161 | return ret; | |
162 | read++; | |
163 | cnt--; | |
164 | } | |
165 | ||
166 | /* Only white space found? */ | |
167 | if (isspace(ch)) { | |
168 | file->f_pos += read; | |
169 | ret = read; | |
170 | return ret; | |
171 | } | |
172 | ||
173 | buf = kmalloc(EVENT_BUF_SIZE+1, GFP_KERNEL); | |
174 | if (!buf) | |
175 | return -ENOMEM; | |
176 | ||
177 | if (cnt > EVENT_BUF_SIZE) | |
178 | cnt = EVENT_BUF_SIZE; | |
179 | ||
180 | i = 0; | |
181 | while (cnt && !isspace(ch)) { | |
182 | if (!i && ch == '!') | |
183 | set = 0; | |
184 | else | |
185 | buf[i++] = ch; | |
186 | ||
187 | ret = get_user(ch, ubuf++); | |
188 | if (ret) | |
189 | goto out_free; | |
190 | read++; | |
191 | cnt--; | |
192 | } | |
193 | buf[i] = 0; | |
194 | ||
195 | file->f_pos += read; | |
196 | ||
197 | ret = ftrace_set_clr_event(buf, set); | |
198 | if (ret) | |
199 | goto out_free; | |
200 | ||
201 | ret = read; | |
202 | ||
203 | out_free: | |
204 | kfree(buf); | |
205 | ||
206 | return ret; | |
207 | } | |
208 | ||
209 | static void * | |
210 | t_next(struct seq_file *m, void *v, loff_t *pos) | |
211 | { | |
212 | struct ftrace_event_call *call = m->private; | |
213 | struct ftrace_event_call *next = call; | |
214 | ||
215 | (*pos)++; | |
216 | ||
217 | if ((unsigned long)call >= (unsigned long)__stop_ftrace_events) | |
218 | return NULL; | |
219 | ||
220 | m->private = ++next; | |
221 | ||
222 | return call; | |
223 | } | |
224 | ||
225 | static void *t_start(struct seq_file *m, loff_t *pos) | |
226 | { | |
227 | return t_next(m, NULL, pos); | |
228 | } | |
229 | ||
230 | static void * | |
231 | s_next(struct seq_file *m, void *v, loff_t *pos) | |
232 | { | |
233 | struct ftrace_event_call *call = m->private; | |
234 | struct ftrace_event_call *next; | |
235 | ||
236 | (*pos)++; | |
237 | ||
238 | retry: | |
239 | if ((unsigned long)call >= (unsigned long)__stop_ftrace_events) | |
240 | return NULL; | |
241 | ||
242 | if (!call->enabled) { | |
243 | call++; | |
244 | goto retry; | |
245 | } | |
246 | ||
247 | next = call; | |
248 | m->private = ++next; | |
249 | ||
250 | return call; | |
251 | } | |
252 | ||
253 | static void *s_start(struct seq_file *m, loff_t *pos) | |
254 | { | |
255 | return s_next(m, NULL, pos); | |
256 | } | |
257 | ||
258 | static int t_show(struct seq_file *m, void *v) | |
259 | { | |
260 | struct ftrace_event_call *call = v; | |
261 | ||
b628b3e6 SR |
262 | if (strcmp(call->system, TRACE_SYSTEM) != 0) |
263 | seq_printf(m, "%s:", call->system); | |
b77e38aa SR |
264 | seq_printf(m, "%s\n", call->name); |
265 | ||
266 | return 0; | |
267 | } | |
268 | ||
269 | static void t_stop(struct seq_file *m, void *p) | |
270 | { | |
271 | } | |
272 | ||
273 | static int | |
274 | ftrace_event_seq_open(struct inode *inode, struct file *file) | |
275 | { | |
276 | int ret; | |
277 | const struct seq_operations *seq_ops; | |
278 | ||
279 | if ((file->f_mode & FMODE_WRITE) && | |
280 | !(file->f_flags & O_APPEND)) | |
281 | ftrace_clear_events(); | |
282 | ||
283 | seq_ops = inode->i_private; | |
284 | ret = seq_open(file, seq_ops); | |
285 | if (!ret) { | |
286 | struct seq_file *m = file->private_data; | |
287 | ||
288 | m->private = __start_ftrace_events; | |
289 | } | |
290 | return ret; | |
291 | } | |
292 | ||
1473e441 SR |
293 | static ssize_t |
294 | event_enable_read(struct file *filp, char __user *ubuf, size_t cnt, | |
295 | loff_t *ppos) | |
296 | { | |
297 | struct ftrace_event_call *call = filp->private_data; | |
298 | char *buf; | |
299 | ||
fd994989 | 300 | if (call->enabled || call->raw_enabled) |
1473e441 SR |
301 | buf = "1\n"; |
302 | else | |
303 | buf = "0\n"; | |
304 | ||
305 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); | |
306 | } | |
307 | ||
308 | static ssize_t | |
309 | event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, | |
310 | loff_t *ppos) | |
311 | { | |
312 | struct ftrace_event_call *call = filp->private_data; | |
313 | char buf[64]; | |
314 | unsigned long val; | |
315 | int ret; | |
316 | ||
317 | if (cnt >= sizeof(buf)) | |
318 | return -EINVAL; | |
319 | ||
320 | if (copy_from_user(&buf, ubuf, cnt)) | |
321 | return -EFAULT; | |
322 | ||
323 | buf[cnt] = 0; | |
324 | ||
325 | ret = strict_strtoul(buf, 10, &val); | |
326 | if (ret < 0) | |
327 | return ret; | |
328 | ||
329 | switch (val) { | |
330 | case 0: | |
1473e441 | 331 | case 1: |
11a241a3 | 332 | mutex_lock(&event_mutex); |
fd994989 | 333 | ftrace_event_enable_disable(call, val); |
11a241a3 | 334 | mutex_unlock(&event_mutex); |
1473e441 SR |
335 | break; |
336 | ||
337 | default: | |
338 | return -EINVAL; | |
339 | } | |
340 | ||
341 | *ppos += cnt; | |
342 | ||
343 | return cnt; | |
344 | } | |
345 | ||
fd994989 SR |
346 | static ssize_t |
347 | event_type_read(struct file *filp, char __user *ubuf, size_t cnt, | |
348 | loff_t *ppos) | |
349 | { | |
350 | struct ftrace_event_call *call = filp->private_data; | |
351 | char buf[16]; | |
352 | int r = 0; | |
353 | ||
354 | if (call->type & TRACE_EVENT_TYPE_PRINTF) | |
355 | r += sprintf(buf, "printf\n"); | |
356 | ||
357 | if (call->type & TRACE_EVENT_TYPE_RAW) | |
358 | r += sprintf(buf+r, "raw\n"); | |
359 | ||
360 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
361 | } | |
362 | ||
363 | static ssize_t | |
364 | event_type_write(struct file *filp, const char __user *ubuf, size_t cnt, | |
365 | loff_t *ppos) | |
366 | { | |
367 | struct ftrace_event_call *call = filp->private_data; | |
368 | char buf[64]; | |
369 | ||
370 | /* | |
371 | * If there's only one type, we can't change it. | |
372 | * And currently we always have printf type, and we | |
373 | * may or may not have raw type. | |
374 | * | |
375 | * This is a redundant check, the file should be read | |
376 | * only if this is the case anyway. | |
377 | */ | |
378 | ||
379 | if (!call->raw_init) | |
380 | return -EPERM; | |
381 | ||
382 | if (cnt >= sizeof(buf)) | |
383 | return -EINVAL; | |
384 | ||
385 | if (copy_from_user(&buf, ubuf, cnt)) | |
386 | return -EFAULT; | |
387 | ||
388 | buf[cnt] = 0; | |
389 | ||
390 | if (!strncmp(buf, "printf", 6) && | |
391 | (!buf[6] || isspace(buf[6]))) { | |
392 | ||
393 | call->type = TRACE_EVENT_TYPE_PRINTF; | |
394 | ||
395 | /* | |
396 | * If raw enabled, the disable it and enable | |
397 | * printf type. | |
398 | */ | |
399 | if (call->raw_enabled) { | |
400 | call->raw_enabled = 0; | |
401 | call->raw_unreg(); | |
402 | ||
403 | call->enabled = 1; | |
404 | call->regfunc(); | |
405 | } | |
406 | ||
407 | } else if (!strncmp(buf, "raw", 3) && | |
408 | (!buf[3] || isspace(buf[3]))) { | |
409 | ||
410 | call->type = TRACE_EVENT_TYPE_RAW; | |
411 | ||
412 | /* | |
413 | * If printf enabled, the disable it and enable | |
414 | * raw type. | |
415 | */ | |
416 | if (call->enabled) { | |
417 | call->enabled = 0; | |
418 | call->unregfunc(); | |
419 | ||
420 | call->raw_enabled = 1; | |
421 | call->raw_reg(); | |
422 | } | |
423 | } else | |
424 | return -EINVAL; | |
425 | ||
426 | *ppos += cnt; | |
427 | ||
428 | return cnt; | |
429 | } | |
430 | ||
431 | static ssize_t | |
432 | event_available_types_read(struct file *filp, char __user *ubuf, size_t cnt, | |
433 | loff_t *ppos) | |
434 | { | |
435 | struct ftrace_event_call *call = filp->private_data; | |
436 | char buf[16]; | |
437 | int r = 0; | |
438 | ||
439 | r += sprintf(buf, "printf\n"); | |
440 | ||
441 | if (call->raw_init) | |
442 | r += sprintf(buf+r, "raw\n"); | |
443 | ||
444 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
445 | } | |
446 | ||
b77e38aa SR |
447 | static const struct seq_operations show_event_seq_ops = { |
448 | .start = t_start, | |
449 | .next = t_next, | |
450 | .show = t_show, | |
451 | .stop = t_stop, | |
452 | }; | |
453 | ||
454 | static const struct seq_operations show_set_event_seq_ops = { | |
455 | .start = s_start, | |
456 | .next = s_next, | |
457 | .show = t_show, | |
458 | .stop = t_stop, | |
459 | }; | |
460 | ||
461 | static const struct file_operations ftrace_avail_fops = { | |
462 | .open = ftrace_event_seq_open, | |
463 | .read = seq_read, | |
464 | .llseek = seq_lseek, | |
465 | .release = seq_release, | |
466 | }; | |
467 | ||
468 | static const struct file_operations ftrace_set_event_fops = { | |
469 | .open = ftrace_event_seq_open, | |
470 | .read = seq_read, | |
471 | .write = ftrace_event_write, | |
472 | .llseek = seq_lseek, | |
473 | .release = seq_release, | |
474 | }; | |
475 | ||
1473e441 SR |
476 | static const struct file_operations ftrace_enable_fops = { |
477 | .open = tracing_open_generic, | |
478 | .read = event_enable_read, | |
479 | .write = event_enable_write, | |
480 | }; | |
481 | ||
fd994989 SR |
482 | static const struct file_operations ftrace_type_fops = { |
483 | .open = tracing_open_generic, | |
484 | .read = event_type_read, | |
485 | .write = event_type_write, | |
486 | }; | |
487 | ||
488 | static const struct file_operations ftrace_available_types_fops = { | |
489 | .open = tracing_open_generic, | |
490 | .read = event_available_types_read, | |
491 | }; | |
492 | ||
1473e441 SR |
493 | static struct dentry *event_trace_events_dir(void) |
494 | { | |
495 | static struct dentry *d_tracer; | |
496 | static struct dentry *d_events; | |
497 | ||
498 | if (d_events) | |
499 | return d_events; | |
500 | ||
501 | d_tracer = tracing_init_dentry(); | |
502 | if (!d_tracer) | |
503 | return NULL; | |
504 | ||
505 | d_events = debugfs_create_dir("events", d_tracer); | |
506 | if (!d_events) | |
507 | pr_warning("Could not create debugfs " | |
508 | "'events' directory\n"); | |
509 | ||
510 | return d_events; | |
511 | } | |
512 | ||
6ecc2d1c SR |
513 | struct event_subsystem { |
514 | struct list_head list; | |
515 | const char *name; | |
516 | struct dentry *entry; | |
517 | }; | |
518 | ||
519 | static LIST_HEAD(event_subsystems); | |
520 | ||
521 | static struct dentry * | |
522 | event_subsystem_dir(const char *name, struct dentry *d_events) | |
523 | { | |
524 | struct event_subsystem *system; | |
525 | ||
526 | /* First see if we did not already create this dir */ | |
527 | list_for_each_entry(system, &event_subsystems, list) { | |
528 | if (strcmp(system->name, name) == 0) | |
529 | return system->entry; | |
530 | } | |
531 | ||
532 | /* need to create new entry */ | |
533 | system = kmalloc(sizeof(*system), GFP_KERNEL); | |
534 | if (!system) { | |
535 | pr_warning("No memory to create event subsystem %s\n", | |
536 | name); | |
537 | return d_events; | |
538 | } | |
539 | ||
540 | system->entry = debugfs_create_dir(name, d_events); | |
541 | if (!system->entry) { | |
542 | pr_warning("Could not create event subsystem %s\n", | |
543 | name); | |
544 | kfree(system); | |
545 | return d_events; | |
546 | } | |
547 | ||
548 | system->name = name; | |
549 | list_add(&system->list, &event_subsystems); | |
550 | ||
551 | return system->entry; | |
552 | } | |
553 | ||
1473e441 SR |
554 | static int |
555 | event_create_dir(struct ftrace_event_call *call, struct dentry *d_events) | |
556 | { | |
557 | struct dentry *entry; | |
fd994989 | 558 | int ret; |
1473e441 | 559 | |
6ecc2d1c SR |
560 | /* |
561 | * If the trace point header did not define TRACE_SYSTEM | |
562 | * then the system would be called "TRACE_SYSTEM". | |
563 | */ | |
564 | if (strcmp(call->system, "TRACE_SYSTEM") != 0) | |
565 | d_events = event_subsystem_dir(call->system, d_events); | |
566 | ||
fd994989 SR |
567 | if (call->raw_init) { |
568 | ret = call->raw_init(); | |
569 | if (ret < 0) { | |
570 | pr_warning("Could not initialize trace point" | |
571 | " events/%s\n", call->name); | |
572 | return ret; | |
573 | } | |
574 | } | |
575 | ||
576 | /* default the output to printf */ | |
577 | call->type = TRACE_EVENT_TYPE_PRINTF; | |
578 | ||
1473e441 SR |
579 | call->dir = debugfs_create_dir(call->name, d_events); |
580 | if (!call->dir) { | |
581 | pr_warning("Could not create debugfs " | |
582 | "'%s' directory\n", call->name); | |
583 | return -1; | |
584 | } | |
585 | ||
586 | entry = debugfs_create_file("enable", 0644, call->dir, call, | |
587 | &ftrace_enable_fops); | |
588 | if (!entry) | |
589 | pr_warning("Could not create debugfs " | |
590 | "'%s/enable' entry\n", call->name); | |
591 | ||
fd994989 SR |
592 | /* Only let type be writable, if we can change it */ |
593 | entry = debugfs_create_file("type", | |
594 | call->raw_init ? 0644 : 0444, | |
595 | call->dir, call, | |
596 | &ftrace_type_fops); | |
597 | if (!entry) | |
598 | pr_warning("Could not create debugfs " | |
599 | "'%s/type' entry\n", call->name); | |
600 | ||
601 | entry = debugfs_create_file("available_types", 0444, call->dir, call, | |
602 | &ftrace_available_types_fops); | |
603 | if (!entry) | |
604 | pr_warning("Could not create debugfs " | |
605 | "'%s/type' available_types\n", call->name); | |
606 | ||
1473e441 SR |
607 | return 0; |
608 | } | |
609 | ||
b77e38aa SR |
610 | static __init int event_trace_init(void) |
611 | { | |
1473e441 | 612 | struct ftrace_event_call *call = __start_ftrace_events; |
b77e38aa SR |
613 | struct dentry *d_tracer; |
614 | struct dentry *entry; | |
1473e441 | 615 | struct dentry *d_events; |
b77e38aa SR |
616 | |
617 | d_tracer = tracing_init_dentry(); | |
618 | if (!d_tracer) | |
619 | return 0; | |
620 | ||
621 | entry = debugfs_create_file("available_events", 0444, d_tracer, | |
622 | (void *)&show_event_seq_ops, | |
623 | &ftrace_avail_fops); | |
624 | if (!entry) | |
625 | pr_warning("Could not create debugfs " | |
626 | "'available_events' entry\n"); | |
627 | ||
628 | entry = debugfs_create_file("set_event", 0644, d_tracer, | |
629 | (void *)&show_set_event_seq_ops, | |
630 | &ftrace_set_event_fops); | |
631 | if (!entry) | |
632 | pr_warning("Could not create debugfs " | |
633 | "'set_event' entry\n"); | |
634 | ||
1473e441 SR |
635 | d_events = event_trace_events_dir(); |
636 | if (!d_events) | |
637 | return 0; | |
638 | ||
639 | events_for_each(call) { | |
640 | /* The linker may leave blanks */ | |
641 | if (!call->name) | |
642 | continue; | |
643 | event_create_dir(call, d_events); | |
644 | } | |
645 | ||
b77e38aa SR |
646 | return 0; |
647 | } | |
648 | fs_initcall(event_trace_init); |